Evaluating Arguments: The Interrogative Model and Ranking of Rivals

The Interrogative Model and Assessment of Argument Strength

  • Ranking of Rivals Strategy: This week's core concept is evaluating the strength of an argument by ranking rival answers to the argument’s implicit question.
    • The ranking serves to determine how well the conclusion and all its alternatives address the implicit question.
    • The ranking is hierarchical: the most likely or plausible answers are placed at the top, and the least likely are placed at the bottom.
  • Defining a Strong Argument: According to the interrogative model, support is intended to recommend the conclusion as the single best answer to the implicit question, superior to all alternatives.
    • The Condition for Strength: An argument is defined as a "strong argument" specifically when the conclusion of that argument is alone at the top of the rankings.
    • The Comparative Nature of Conclusions: Being a "good" conclusion is a relative notion. Its status is always compared to alternative rivals or different possible answers to the implicit question.
  • Schematization and Practice Evaluation:
    • In a schematized argument where claimants are abstract (e.g., C2 as a conclusion), specific rankings determine strength:
      • If a ranking shows C2 at the top but tied with C3, the argument is weak because it fails to rule out specific competitors. It only shows the conclusion is as good as another option, failing to prove it is the correct answer.
      • The argument is only convincing if the conclusion holds the top position without competitors.

The Function and Relevance of Support

  • Defining Relevance in the Interrogative Model: Support is relevant to an argument because it contributes directly to determining the rankings of the rivals.
    • Support consists of information from a passage that affects the plausibility of specific rivals.
  • How Support Affects Rankings: An item of support makes a specific rival better or worse at answering the implicit question.
    • This results in raising or lowering that rival within the hierarchy of the rankings.
    • Single vs. Multiple Contributions: A single item of support can affect more than one rival simultaneously. It might raise one rival while lowering others at the same time.

Case Study: The Midnight Disturbance

  • Context: The speaker was woken up at 3 a.m. by sirens and flashing lights. In the morning, new tire marks were visible.
  • Implicit Question (IQ): "What woke me up last night?" or "What were those lights and sounds that roused me from my sleep?"
  • The Conclusion (C1): The local kids were out doing car tricks.
  • The Rivals:
    • C2: It was a construction crew. (Included because the speaker mentions construction in the passage).
    • C3: It was a police chase.
  • Support Analysis:
    • S1 (Sirens passing and flashing lights):
      • Raises C3 (Police chase) because a police chase involves sirens and lights.
      • Lowers C2 (Construction crew) because construction crews rarely use sirens.
      • Lowers C1 (Kids) because kids' regular cars do not have sirens or flashing lights (though not impossible, it is less likely).
    • S3 (Construction not allowed in the neighborhood at night):
      • Lowers C2 in the rankings. If construction is prohibited, it makes the construction crew a poor answer to the IQ.
    • S4 (Local teens recently installing light rigs to their cars):
      • This new hypothetical information would raise C1 (the conclusion) in the rankings because it explains the flashing lights portion of the IQ.
      • However, S4 likely does not put C1 at the single top position because it does not account for the sirens (only the lights).

Articulating the Relevance of Support

  • Definition of Articulating: To put into words or express clearly.
  • The Framework for Expressing Contribution: To articulate relevance, one must state exactly how support affects the rivals’ rankings. This involves three steps:
    1. Identify the specific item of support.
    2. Identify the rival(s) it is directly relevant for.
    3. Specify whether it raises or lowers those rivals in the ranking.
  • Examples of Articulation:
    • "S2 raises C1 in the rankings."
    • "S4 lowers C2, but it raises C3 in the rankings."
    • "S5 lowers both C3 and C4 in the rankings."

Case Study: Art Center Tickets

  • Implicit Question: What should we do with these unused tickets?
  • Conclusion (C1): Give unused tickets to students and senior citizens.
  • Rivals:
    • C2: Do nothing (status quo).
    • C3: Sell unused tickets at a discount on performance days.
  • Support Analysis:
    • S1 (The proposed plan would benefit the arts in the long run):
      • Directly relevant to C1. It raises C1 in the rankings by providing a reason for that specific answer.
    • S2 (High school drama students who cannot afford tickets would better learn their trade):
      • Raises C1. It specifically addresses why students should receive tickets.
      • May also raise C3 to a lesser extent (if the discount makes tickets affordable), but it raises C1 more directly.
    • S3 (The need to put "butts in seats"):
      • Raises both C1 and C3. Filling seats is a goal addressed by both giving tickets away and selling them at a discount.
    • S4 (Last year, a marketing program for discounted tickets did not significantly increase sales):
      • Lowers C3 in the rankings. It provides empirical evidence suggesting that discounting tickets is an ineffective solution, making C3 a worse answer to the IQ.

Case Study: The Air Conditioner Diagnostic

  • Implicit Question: Why did the air conditioner shut off?
  • Conclusion (C1): The unit is broken.
  • Rivals:
    • C2: A fuse blew in the apartment. (Assumption: the fuse is in the apartment, not the machine).
    • C3: A localized power outage.
    • C4: Someone else turned off the AC unit remotely.
  • Support Analysis:
    • S3 (The lights remained on in the apartment):
      • Lowers C3 (Power outage) because if the power were out, the lights would be off.
      • Lowers C2 (Fuse blew) because a blown fuse typically shuts off power to a range of outlets/lights. While possible it only affected the AC outlet, it is less likely than other explanations.
      • Does not directly raise C1 or C4, but helps them by comparison/ruling out competitors.
    • S4 (The AC unit was old):
      • Raises C1 in the rankings. Old machinery is prone to breaking, making the "unit broke" answer more plausible.
    • S5 (The unit came with a remote control that hasn't been seen in months):
      • Raises C4. It provides a mechanism (the remote) and a reason (it is missing/someone else might have it) to support the remote-shutoff theory.
  • Diagnostic Arguments: These involve making a diagnosis or figuring out cause-and-effect. In later weeks, the class will use language of "what explains what" to further articulate relevance.

Case Study: Simone the Cat

  • Implicit Question: Where is Simone?
  • Conclusion (C1): Simone got out of the apartment through the bathroom window.
  • Rivals:
    • C2: Simone is hiding somewhere in the apartment.
    • C3: Someone came into the apartment and took Simone (catnapping).
  • Support Analysis:
    • S3 (A large clump of white fur on the external windowsill):
      • Raises C1. It provides physical evidence that the cat was at the point of exit.
      • Student discussion suggested it might lower C3, but the instructor noted that it is hard to see a direct link there—it primarily raises C1.
  • Hypothetical New Information (Raising C3):
    • S6: The window was found broken (Though this might change the scenario rather than being a new clue).
    • S7: Boot prints found in the house near the open window.
    • S8: Neighbors complained about suspicious individuals around the complex.
    • S9: The cat carrier is missing (Directly raises C3 as it explains how the cat was transported).
    • S10: A roommate who hates the cat or is weirdly obsessed with the cat.
    • S11: Signs of forced entry on the front door (Radically changes the rankings, making C3 much more serious).
    • S12: Trend of missing cats in the neighborhood.

Case Study: The Travis Busby Disappearance

  • Case Details:
    • Travis Busby (56 years old), experienced sailor from Colton.
    • Boat: "Forever Amber" (43-foot), found drifting off Point Loma.
    • Evidence on boat: Blood-splattered; .22-caliber handgun found (fired once, 5 rounds remaining, hammer on empty shell); fuel tanks empty (432 gallons taken on Jan 4th); navigational lights on; billfold, dingy, and uninflated life raft present.
    • History: Busby was depressed about significant financial problems.
  • Implicit Question: What happened to Travis Busby?
  • Rivals:
    • C1: Suicide.
    • C2: Murder.
    • C3: Accident.
    • C4: Faked his death / Still alive.
  • Support Evaluation:
    • S1 (Busby was depressed about financial problems):
      • Raises C1 (Suicide) and C4 (Faked death to escape debt).
      • Potentially raises C2 (Murder) if he owed money to the wrong people.
    • S2 (Busby recently took out a large life insurance policy):
      • Raises C4 (Part of a plan to disappear/provide for family).
      • Raises C2 (Provides a motive for someone else to murder him).
    • S3 (Busby recently completed a gun safety training program):
      • Lowers C3 (Accident) because a safety-trained person is less likely to have a gun accident.
      • May raise C1 or C2 by suggesting the recent acquisition of a weapon for a specific purpose (protection or self-harm).
    • S4 (A sighting of someone matching Busby's description in Tijuana):
      • Raises C4 significantly in the rankings.

Questions & Discussion

  • Question on Argument Strength: A student asked why Option B in the schematized quiz (conclusion C2 tied for top) wasn't a strong argument.
    • Response: The instructor clarified that an argument is not convincing if there is another equally plausible option on the table. It must show the conclusion is better than alternatives, not just as good.
  • Question on S1 in the Disturbance Case: A student asked if S1 (sirens/lights) would lower the other two rivals while raising C3 (police chase).
    • Response: Yes. It raises C3 because it accounts for the sirens, and simultaneously lowers C2 (construction) and C1 (kids) because they typically lack that equipment.
  • Question on the Art Center Case S2: A student suggested S2 (high school drama students) also raises C3.
    • Response: The instructor agreed it might raise C3 to a lesser extent than C1, as discounted tickets could help those students, though C1 specifically mentions students.
  • Question on the Air Conditioner Case S3: A student asked if S3 (lights on) raises C4 by comparison.
    • Response: The instructor cautioned that while S3 helps C4 by ruling out competitors like C3 and C2, it does not directly raise C4. It is better to focus on the rivals that the support directly affects.
  • Hypothesizing New Evidence for Simone: Students suggested various clues like boot prints (S7) or roommates (S10) to raise C3. The instructor noted that finding signs of forced entry (S11) would radically change how one would rank rivals.
  • Gun Safety and Travis Busby: One student suggested gun safety training (S3) might raise the accident rival (C3) by making him more likely to "play" with the gun.
    • Response: The instructor disagreed, stating the most direct connection is that safety training decreases the likelihood of accidents, thus lowering C3.
    • Follow-up: A student suggested C3 could be a non-gun accident. The instructor noted that separating C3 (non-gun accident) from C5 (gun accident) would require specific reasons to rework the rival list.

Logistics and Reminders

  • Upcoming Focus: The remainder of the term (week and a half) will focus on using the language of "explanation" to understand rankings and diagnostic arguments.
  • Homework Requirements: When stating how support affects rankings, students must identify the item of support, the specific rivals affected, and whether it raises or lowers them.
  • Holiday Notice: There is no class on Monday due to a university holiday. The next session is Wednesday (one week from the transcript date).